Our Voyage from Catalytic Cross-Hydroalkenylation to Transfer-Dehydroaromatization of Cyclic π-Systems: Reactivity and Selectivity Changes Enabled by NHC-Ni and NHC-Pd Hydride Equivalents

Abstract

AbstractN-Heterocyclic carbene ligated transition-metal catalysts often show interesting properties and reactivity as compared to conventional ligand systems. In (NHC)Ni and (NHC)Pd hydrides, a dramatic reactivity changed from cross-hydroalkenylation to transfer-dehydroaromatization was observed under optimized conditions. This account summarizes our recent efforts and stories behind this serendipitous discovery. The mechanistic studies revealed that the keys to divert the desired reactivity are the differences in the olefin insertion selectivity and the hydrometallated species reactivity.